First costume. Police officer from Fifth Element. Please help with material selection

[CzarAlex]

One of my goals in life is to go to a Con dressed up in a cosplay costume. I've chosen to go as a Police officer from The Fifth Element but have just about NO clue where to start. I've never made a costume before.

Where do I even begin?

http://i.imgur.com/hYFof6Q.jpg
http://i.imgur.com/IEUDLSH.jpg
http://i.imgur.com/gBMui9x.jpg

It looks like the shoulders are modified shoulder pads from some sort of sport (football, it seems) and I'm sure I can find a used set somewhere. What specific material would you suggest I use to modify the rest of those pads? Is it some sort of foam? (If so, what is it called?) Something else I can shape?

Any ideas at all regarding what to use for a base for the helmet? What materials to use to get that shape?

Also, when I comes to the gun, what sort of material do you recommend I make it out of?

http://i.imgur.com/S0Tf2HR.jpg

I appreciate any and all help you give me regarding this.

 

[Arch27]

Re: First costume. Police officer from Fifth Element. Please help with material selec

Here's a good shot from an auction site - It's clean and bright so you can see the pieces.

 

[CzarAlex]

Re: First costume. Police officer from Fifth Element. Please help with material selec

Thanks. I went through a blueray version of the movie and took a metric poop ton of screen caps. I'll add this to the collection.

 

[Arch27]

Re: First costume. Police officer from Fifth Element. Please help with material selec

Here's a site with some more decent shots.
Fifth Element Costumes Photos by lostncybr | Photobucket

Also this auction
http://www.screenused.com/index.cfm?sectionID=item-detail&subsectionID=index.cfm&item_id=2352